Remote measuring system



April 27, 1937. c. OMAN 2,078,680

REMOTE MEASURING SYSTEM Filed May 11, 1955 2 :"Q' I""T* l 24 l as a5 a4?I 0 5 ili a as L I I JI F3 l r Ina/cafi/gr E o/ fiecolvl'ny L6: i2 MeferWITNESSES: J INVENTOR Patented Apr. 27, 1937 UNUSED STATES PAT? FFICEREMOTE MEASURING SYSTEM East Pittsburgh, Pa. sylvania Application May11,

9 Claims.

My invention relates, generally, to measuring or telemeter systems, and,more particularly, to remote measuring and indicating systems of theimpulse type, wherein electrical impulses or impulse efiects areproduced by a transmitter in response to a current, power or voltagecharacteristic of a circuit or in response to any other characteristicor quantity which is to be indicated or recorded at a remote station.

The object of my invention generally stated is to provide a remotemeasuring or telemeter system which shall be of simple construction,ethcient and accurate in operation and which may be readily andeconomically manufactured and installed.

A more specific object of my invention is to provide a remote measuringsystem wherein the receiver is unafiected by variations in the voltageof the power source at the receiving station.

Another object of my invention is to provide for utilizing an impulsefilter in an impulse remote measuring system to control the functioningof the meter or indicating device in response to the impulses received.

A still further object of my invention is to provide for supplying thereceiver of an impulse measuring system with a constant operatingvoltage by means of a voltage regulator.

A further object of my invention is to provide a receiver for a remotemeasuring or telemeter system of the impulse condenser type wherein thecondenser impulses are stored and the stored energy gradually fed to themeter or indicating device.

A still further object of my invention is to provide, in a remotemeasuring or telemeter receiver comprising a meter and calibratingcondenser, for storing the condenser charging impulses and graduallyfeeding the stored energy to the meter.

Another object of my invention is to provide a telemetering receiver ofthe impulse condenser type which is unaifected by variations in thevoltage of its power source and wherein the meter or indicating deviceis actuated by leakage current from a condenser storage reservoirreceiving energy from an impulse or calibration condenser.

These and other objects of the invention will become more apparent froma study of the following detailed description in conjunction with thedrawing wherein the single figure constitutes a diagrammaticillustration of aremote measuring or telemeter system embodying theprincipal features of my invention.

In practicing my invention in its preferred a corporation of Penn- 1935,Serial No. 21,009

form, an impulse or calibration condenser which provides the energy foroperating the indicating or recording meter is alternately charged anddischarged with reversed polarity from a source of direct currentthrough the operation of a reversing switch or relay. The reversingswitch is actuated by current impulses transmitted over a suitablechannel by an impulse transmitter which may be in the form of a contactmaking watthour meter, or the like, which transmits impulses inaccordance with the quantity being measured. The calibration condenseris connected to a direct current power source at the receiving sta tionthrough a suitable voltage regulator such, for example, as a glowdischarge tube in order to subject the condenser to a constant chargingvoltage and thereby insure a uniform charging current for each impulse.The charging current of the calibration condenser is prevented fromflowing directly into the meter or indicating device by means of a chokecoil and is directed into a filter or condenser reservoir comprising alarge condenser and a rectifier having a resistor in parallel therewith.The energy stored in the reservoir slowly leaks out through the resistorand fiows through the meter circuit which gives the meter a smoothaction and produces a deflection substantially proportional to theimpulse rate.

Referring now to the drawing, there is shown at It! an impulsetransmitter which is adapted to transmit current impulses over asuitable channel represented by line conductors H at a rate dependentupon the magnitude of a quantity or characteristic that is to beindicated or recorded at a remote station.

In this instance, the transmitter I0 is in the form of a watthour meterhaving a moving element I2 provided with a commutator l3 and cooperatingbrushes H! which are connected to the transmitting channel H energizedby a source of direct current power 55, as shown. As will be readilyunderstood, the watthour meter may be connected to measure the powerflowing in a load circuit and thereby transmit impulses at a rateproportional to the quantity of power in the circuit or any othersuitable device may be used for transmitting impulses in accordance witha predetermined quantity or characteristic.-

In order to indicate or record or both indicate and record themeasurement at a remote station, there is provided a meter or instrument56. In this instance, the meter I6 is illustrated as a direct currentmilliammeter.

The instrument I6 is actuated in accordance with the rate at which theimpulses are transmitted from the sending station by a local source ofenergy represented as a battery I? of large capacity and voltage.

The principal features of this invention reside in the provisions madefor efiecting the operation of the instrument is in a smooth and steadymanner and to cause it to accurately function in accordance with theimpulse rate or in other words to accurately reproduce the measurementmade at the transmitting station.

The energization of the instrument I6 is controlled primarily by meansof a small condenser 88 which may be referred to as a calibrationcondenser. The charging and discharging of the calibration condenser i8is controlled by a reversing switch 59 which, when operated, functionsto alternately charge the condenser in opposite directions from thedirect-current source or station battery l'l.

Any suitable type of reversing switch may be used such for example as atelephone relay as shown diagrammatically having back contacts 2! and22, front contacts 23 and 26, with cooperating armatures 25 and 23actuated by the coil 2? connected in the transmitting circuit ii.

As will be observed, when the reversing switch i9 is deenergized, asshown, the calibration condenser IB is connected across the source H inseries with the instrument l6 through the back contacts 2i and 22 whichcharges the condenser with current of one polarity. When the revers ingswitch is actuated, the condenser is discharged and charged with currentof the opposite polarity through the contacts 23 and 25.

It is apparent that regardless of the position of the reversing switchE9, the charging current impulses of the calibration condenser i8 alwaysflow in the same direction through the conductors 3! and 32 of theinstrument circuit. In this instance, the calibration condenser i8 is ofsuch capacity that it is fully charged and discharged in response toeach operation of the reversing switch l9 regardless of the speed atwhich the impulses from the transmitter are received.

In order that the meter l6 may be caused to accurately reproduce themeasurement at the transmitting system, it is necessary that thecalibration condenser l8 be charged with a definite quantity ofelectricity for each impulse. The total quantity of electricity which isthen sent through the meter i6 is proportional to the impulse rate.

In order to accomplish this function, provision is made for maintainingthe voltage, to which the calibration condenser is subjected by theoperations of the reversing switch, at a substantially constant value atall times. This is accomplished by means of a suitable voltage regulator33 interposed between the station battery H and the calibrationcondenser 58. As will be readily understood, the voltage of the stationbattery may vary over a considerable range due to heavy loads andcharging operations and, therefore, it is necessary to utilize a voltageregulator of some type to control the voltage to which the calibrationcondenser is subjected.

In this instance, the voltage regulator 33 is of the electronic typecomprising a glow discharge tube 33., a condenser 35 and a limitingresistor 36. The tube 3% functions to maintain the voltage drop acrossits terminals at a constant value, such, for example, as at volts Wherethe voltage of the station battery may vary from to volts. It is to beunderstood, however, that any other suitable type of regulator may beutilized instead of the electronic type illustrated. It is now apparentthat the operation of the reversing switch IS in reversely charging thecali bration condenser ii to full capacity provides for the flow of adefinite amount of current in the charging circuit for each impulsetransmitted. Due to the connections of the reversing switch to theconstant voltage power source, comprising battery 11 and regulator 33and to the condenser is, the charging currents, regardless of thepolarity of the condenser, always flow through the charging circuit andinto the stori age condenser 38 in the same direction. Thus the energywhich is stored in the storage condenser 38 is always proportional tothe quantity being measured by the transmitter It].

In order to steady the operation of the meter it and. to cause it todeflect or record substantially proportional to the impulse rate,provision is made for storing the charging current impulses of thecalibration condenser i8 and'gradually feeding the stored energy to themeter.

In this instance, this is accomplished by means of an impulse filter 3iinterposed between the calibration condenser and the meter. The filtercomprises generally a storage condenser 38, of

large capacity as compared to the capacity. of

the calibration condenser l8, and a valve or rectifier device 39connected in parallel with the meter. The rectifier or valve 39 isillustrated in the form of a Rectox valve although any other suitabletype of unidirectional device may be used.

In order that the charging current impulses flowing in the meter circuitmay be directed into the storage condenser 38, a choke coil 4! isinterposed in the circuit in order to resist the flow w of impulses, thepath of the least resistance then being through the valve 33 into thestorage con denser 38.

In order to provide for gradually feeding the stored energy to the meterl6, a leakage resistor I 42 is connected in shunt relation with thevalve 39. As will be readily understood, this provides a path for theenergy stored in the storage condenser 38 to gradually leak back throughthe choke coil 4| into the'meter circuit, the result being that themeter has a smooth action and produces a deflection in proportion to theimpulse rate.

In view of the foregoing, it is apparent that the invention has twoimportant aspects, namely the provision for producing uniform impulseconditions at the receiver regardless of variations in the source ofvoltage and in transforming these uniform impulses into a steady flow ofcurrent for energizing the indicating or recording meter. No specialapparatus in the form of transformers or the like is required in orderto produce this overall result.

While the system disclosed is particularly adapted for high rate impulseoperation used primarily for load indication, it is apparent that it maybe also utilized for other telemeter purposes.

Since certain changes may be made in the above described constructionand different embodiments of the invention may be made without departingfrom the spirit thereof, as set forth in the appended claims, it isintended that all matter contained in the above description or shown inthe accompanying drawing shall be inaerated terpreted as illustrativeand not in a limiting sense.

I claim as my invention:

1. An impulse measuring system comprising" means for transmittingcurrent impulses-at a rate proportional to a measurement rate, acalibration condenser, a source of constant voltage power, meansresponsive to the impulses for alternately charging the calibrationcondenser to full capacity with current of opposite polarity from saidpower source, an electrical measuring instrument connected in thecondenser charging circuit, and means including a second condenserconnected in parallel circuit relation to the meas uring instrument forreceiving and storing the charging current impulses of the calibrationcondenser and gradually feeding the stored energy to the measuringinstrument.

2. An impulse measuring system comprising means for transmitting currentimpulses at a rate proportional to a measurement rate, a calibrationcondenser, a source of constant voltage power means responsive to theimpulses for alternately charging the calibration condenser to fullcapacity with current of opposite polarity from said power source, anelectrical measuring instrument connected in the calibration condensercharging circuit means including a uni-directional current conductingdevice and a storage condenser interposed between the calibrationcondenser and measuring instrument for receiving and storing thecondenser charging currents, and means associated with theuni-directional current conducting device whereby the accumulated energyin the storage condenser may slowly leak back through the measuringinstrument.

3. In an impulse measuring system, in combination, an impulsetransmitter, switching means. actuated in accordance with the rate ofoperation of the transmitter, a source of constant voltage, a firstcondenser alternately charged to full capacity in opposite directionsfrom said source of constant voltage in response to the operation of theswitching means, a meter connected in the charging circuit, and meansincluding a second condenser of relatively large capacity interposed inthe charging circuit adapted to receive and store the charging impulsesand for gradually feeding the stored energy to the meter.

4. In an impulse measuring system, an impulse transmitter at thetransmitting station, reversing switch means at the receiving stationresponsive to the impulses produced by the transmitter, a source ofconstant voltage power, a calibration condenser which is alternatelycharged in opposite directions from the power source by the reversingswitch, said condenser being of such capacity that it is completelycharged on each operation of the reversing switch, a rectifier andstorage condenser of relatively large capacity connected in seriescircuit relation with the calibration condenser, a meter connected inparallel circuit relation with the rectifier and storage condenser,means interposed in the meter circuit to direct the charging currentimpulses of the calibration condenser into the storage condenser throughthe rectifier, and means associated with the rectifier whereby thestored energy in the storage condenser may gradually feed back throughthe meter.

5. In an impulse measuring system, an impulse transmitter operable totransmit current impulses at a rate proportional to a quantity orcondition affecting the transmitter, a reversing constant voltage power,a calibration condenser, a storage condenser, a rectifier device, saidcondensers and rectifier device being connected across the power sourcethrough the reversing switch whereby the operation of the reversingswitch alternately charges the calibration condenser in oppositedirections and discharges it, a meter connected across the rectifier andstorage condenser, means in the meter circuit for directing the chargingcurrent impulses of the calibration condenser into the storage condenserand means associated with the rectifier to permit the stored energy inthe storage condenser to gradually fiow into the meter circuit.

6. In an impulse measuring system, an impulse transmitter operable totransmit current impulses at a rate proportional to a quantity orcondition affecting the transmitter, a reversing switch responsive tosaid impulses, a source of constant voltage power, a calibrationcondenser, a storage condenser, a rectifier device, said condensers andrectifier device being connected across the power source through thereversing switch whereby the operation of the reversing switchalternately charges the calibration condenser in opposite directions anddischarges it through the rectifier device into the storage condenser, ameter connected across the rectifier and storage condenser, a choke coilin the meter circuit to prevent the charging current impulses of thecalibration condenser from flowing through the meter and for causing aflow of said impulses into the storage condenser, and a resistorconnected in shunt relation with the rectifier whereby the energy storedin the storage condenser may gradually fiow through the meter.

7. In an impulse measuring system, means for transmitting currentimpulses at a rate proportional to a measurement, a calibrationcondenser, a source of constant voltage power, switch means responsiveto said impulses for alternately charging said condenser with oppositepolarity to full capacity from the power source, a measuring instrumentconnected in the charging circuit, and means interposed between themeasuring instrument and calibration condenser adapted to receive andstore the charging currents and gradually feed the stored energy to themeasuring instrument.

8. In an impulse measuring system, an impulse transmitter at thetransmitting station, a reversing switch at the receiving stationactuated by the impulses produced by the transmitter, a source ofconstant voltage power, a calibration condenser disposed to bealternately charged with opposite polarity from the power source by thereversing switch, said condenser being of such capacity that it is fullycharged on each operation of the reversing switch, a meter, and meansconnecting the meter to the calibration condenser and power sourceadapted to collect and store the charging currents of the calibrationcondenser and gradually feed the stored energy to the meter.

9. In an impulse measuring system, in combination, an impulsetransmitter for transmitting current impulses at a rate dependent on themagnitude of a measured quantity, a meter to be actuated in accordancewith the measured quantity, a source of constant voltage power, acalibration condenser, a circuit including said meter for charging thecondenser from the power source, means actuated by said current impulsesfor switch responsive tosaid impulses, a source ofalternately reversingthe circuit connections to the condenser to fully charge the condenserwith opposite polarity and discharge said condenser in response to eachimpulse, and means 5; including a second condenser interposed in thecharging circuit between the meter and the calibration condenser andpower source for preventing the flow of charging currents through themeter and for collecting the charging currents and gradually feeding thestored energy to the meter.

CARL OMAN.

